8509721778432 has 432 divisors, whose sum is σ = 28586083623552. Its totient is φ = 2384301588480.

The previous prime is 8509721778409. The next prime is 8509721778443. The reversal of 8509721778432 is 2348771279058.

8509721778432 is a `hidden beast` number, since 8 + 50 + 9 + 72 + 17 + 78 + 432 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a self number, because there is not a number n which added to its sum of digits gives 8509721778432.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 331530463 + ... + 331556129.

Almost surely, 2^{8509721778432} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 8509721778432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14293041811776).

8509721778432 is an abundant number, since it is smaller than the sum of its proper divisors (20076361845120).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

8509721778432 is a wasteful number, since it uses less digits than its factorization.

8509721778432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26094 (or 26077 counting only the distinct ones).

The product of its (nonzero) digits is 47416320, while the sum is 63.

The spelling of 8509721778432 in words is "eight trillion, five hundred nine billion, seven hundred twenty-one million, seven hundred seventy-eight thousand, four hundred thirty-two".